1. Field of the Invention
The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device having a color filter.
2. Discussion of the Related Art
An organic light emitting display device includes an organic light emitting element provided with a light emitting layer formed between a cathode and an anode, wherein electrons are injected into the light emitting layer from the cathode, and holes are injected into the light emitting layer from the anode. If the electrons generated in the cathode and the holes generated in the anode are injected into the light emitting layer, an exciton is generated by combination of the injected electrons and holes. The generated exciton is then transited from the excited state to a ground state, whereby light is emitted to display picture images.
Such an organic light emitting display device provides a full color by emitting red (R) light, green (G) light, and blue (B) light for each pixel. To this end, the organic light emitting display device may include a pixel having a light emitting layer emitting red (R) light, a pixel having a light emitting layer emitting green (G) light, and a pixel having a light emitting layer emitting blue (B) light, thereby providing a full color. Alternatively, the organic light emitting display device may provide a full color in such a manner that light emitting layers of all the pixels emit white (W) light and color filters of red (R), green (G) and blue (B) are additionally provided for each pixel.
Hereinafter, an organic light emitting display device of the related art will be described, in which color filters different from one another for each pixel are provided to obtain a full color.
FIG. 1 is a brief cross-sectional view illustrating an organic light emitting display device of the related art.
As shown in FIG. 1, the organic light emitting display device of the related art includes a lower substrate 10, an upper substrate 20, and an adhesive layer 30. A thin film transistor layer 11, which includes a switching thin film transistor and a driving thin film transistor, is formed on the lower substrate 10, a lower electrode 13 is formed on the thin film transistor layer 11, and a bank layer 15 for defining a light emitting region is formed on the lower electrode 13.
Also, a light emitting layer 17 for emitting white (W) light is formed on the lower electrode 13, and an upper electrode 19 is formed on the light emitting layer 17.
Light shielding layers 21 for preventing light leakage from occurring are formed between respective pixels on the upper substrate 20 in a matrix arrangement, wherein color filters 23 of red (R), green (G) and blue (B) are respectively formed between the respective light shielding layers 21 of the matrix arrangement. The adhesive layer 30 is formed between the lower substrate 10 and the upper substrate 20 to adhere these substrates to each other.
The aforementioned organic light emitting display device of the related art displays a picture image in such a manner that white (W) light emitted from the light emitting layer 17 is emitted upwardly and then passes through the color filter 23 of each pixel to transmit light only of a predetermined color.
However, in the aforementioned organic light emitting display device of the related art, the light emitted from the light emitting layer 17 in each pixel passes through the color filter 23 of another adjacent pixel due to the interval between the light emitting layer 17 and the color filter 23, whereby a color of desired gray scale is not displayed. As a result, a problem occurs in that picture quality is deteriorated.